From the past, a large number of chemical fungicides have been used. However, it has become obvious that there is a problem of resistance of plant pathogens against chemical active ingredients associated with frequent use or overdose of such chemical active ingredients with the same action having a similar skeleton for controlling diseases of the same kind.
On the other hand, in late years, consumer's needs for crops with reduced agricultural chemicals or social needs for reduced environmental burdens of chemical pesticides.
Furthermore, in a farm field where chemicals are actually used, when two or more kinds of chemicals are mixed together using a tank mixing method for the treatment, active ingredients which are incompatible with each other are combined, causing lots of risks such as reduced effects of each active ingredients or phytotoxicity suffering to the plants.
Under these circumstances, compositions for preventing plant diseases with significant effect against fungi resistant to the existing active ingredients and with great effect even in a much smaller amount of an active ingredient have been in demand. Furthermore, in order to prevent plant pathogens from having chemical resistance as well, there have been demanded a composition for preventing plant diseases with good compatibility comprising components (compounds) with different actions having different basic skeletons, and a method for preventing the plant diseases.
In JP Patent Publication No. 1997-235282A and European Patent Publication No. 737682 is disclosed
(RS)—N-[2-(1,3-dimethylbutyl)thiophen-3-yl]-1-methyl-3-tri fluoromethyl-1H-pyrazole-4-carboxamide (a common name: penthiopyrad (currently applied for ISO), hereinafter referred to as penthiopyrad) which has a control effect against various diseases.
[Patent Document 1] JP Patent Publication No. 1997-235282A
[Patent Document 2] European Patent Publication No. 737682 (EP0737682)